Thermostat.



No. 813,403. PATENTED FEB. 27, 1906. A. n. OOLTON.

THERMOSTAT.

APPLICATION FILED AUG. 22, 1904.

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UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Feb. 27, 1906.

A lication M August 22, 1904- Serial no. 221,785-

may be maintained at a predetermined de ree.

a The object of my invention is to produce a simple and inexpensive but eflicient and reliable thermostat and also to provide means for bodily shifting or adjusting the electrical contacts with relation to a circuit-closer, which adjustment is in addition or supplemental to their independent adjustment toward and away from each other.

In the drawings, Figure 1 is an elevation of my improved thermostat; Fig. 2, a side elevation thereof; Fig. 3, a sectional elevation on the line 3 3 of Fig. 2, such section being taken just within the line of the face-plate to expose the parts therewithin; Fig. 4, a plan view of the thermostat, and Fig. 5 a detailed view of one of the workin parts.

It will be understood that the parts illustrated in the drawings are simply the interior parts of the thermostat proper and that such parts are in practice incased in a suitable casing, which is generally of an ornamental character; but as such casing is immaterial to an understanding of the invention the same has not been illustrated.

As herein shown, the thermostat comprises a base-plate 1, on which the various operating parts are mounted and which carries in front thereof a face-plate 2, secured to the plate 1 by means of screws 3, passing through distance-sleeves 4. The face-plate has formed thereupon (or attached thereto as a separate member) an indicating-scale, as shown in Fig. 1. It is obvious, however, that the construction just described represents mere mechanical details, which can be varied as desired.

The e-Xpansible and contractible member consists of a longitudinally-extending strip 5,

referabl of hard rubber, and secured at its ower cut to a block 6, fastened to or formed integral with the base-plate. Toward its upper end this strip works freely through an opening in a guide-lug 7, above which its end projects. This upper end isprovided with a cap or sleeve 8, aving a rojecting arm 9, extending obliquely towarcfthe center line of the thermostat for connection with the circuit-closer, as hereinafter explained.

The .circui't-closer comprises a lon itudinally-extending vertical bar 10, pivote at its upper end on a pivot-pin 11 which has its beari respectively in the base-plate and in an an Ie-plate 12, secured to such base-plate, as in icated in Figs. 3 and 4. This bar has a short arm 13, extending laterall from its upper end and pivotally connecte to the upper or free end 9 of the sleeve 8. It will be seen that owing to the connection of the expansi ble member 5 to the short arm of the circuitcloser, which is, in effect, a lever, a slight movement of the strip or member 5 will be multi lied at the lower end of the lever or circuit-c oser, which pla s between the electrical' contacts hereina ter described.

For thepurpose of maintaining the circuitcloser or lever in a normal position intermediate the contacts and a certain predetermined distance from the strip or member 5 I provide a coil-spring 14 and interpose the same between the stri 5 and the circuitcloser or bar 10, as clear y indicated in Fig. 3.

Electrical contacts 15 and 16 are carried on the ends of the adjusting-screws 17 and .18, respectively, which pass diametrically through the two similar posts 19, respectively. The lower end of the circuit-closer or bar 10 depends between these contacts, as described, and is normally positioned at an intermediate position out of contact with either one of such contacts, as seen in Fig. 3.

The two posts 19 instead of being secured or connected with the base-plate in fixed relation therewith are mounted upon a flat plate 20, made of insulating material, preferably hard rubber, and arranged to slide transversely of the base-plate in a guideway formed in suitable manner, as by means of screws 21, pro erly disposed for that purpose. 'By re erence a thin binding-strip of metal 22 is arranged on the up er edge and around the upper corner of the p ate 20.

The plate 20 is, in fact, a rack, inasmuch as it is provided on its lower edge with teeth 23, which are engaged by the teeth of a pinion or segment 24. (Illustrated in detall in Fig. 5.) This segment is formed on a shaft or rod 25, having hearings in the plates 1 and 2 and extendin beyond the latter plate, where it is provided with a cross-pin 26 to enable the shaft to be easily turned or adjusted by the operator.

The shaft 25 carries an indicator or pointer 27, which extends upwardly and is movable over the face of the dial formed on the faceplate 2, Fig. 1. It will be understood that this ointer is adjusted to a position corres on ing with the temperature desired in t e room. For instance, in Fig. 1 this pointer now indicates degrees, which is the desired temperature; but in case a temperature of is desired this pointer is moved to the right, Fig. 1, until it indicates or points to 75 on the dial. It will be observed, however, that in this movement or adjustment of the pointer the rack has likewise been shifted to the right, with the result that the post 19 and the electrical contacts 15 and 16 carried thereby are bodily shifted with relation to the circuit-closer or bar 10. Consequently one of the electrical contacts will be relatively nearer to bar 10 than the other, with the result that on a slight lowering of the temperature the circuit will be closed and the temperature thereby maintained at the desired degree.

It is obvious that the distance between thetwo contacts is adjusted b means of the screws 17 and 18 and also t t such adjustments are independent. As soon as the proper adjustment of these screws is made suc screws are locked in set position by means of set-screws 28, entering the top of the posts 19 and ada ted to bear a ainst the adjusting-screws. o accommo ate the movement of the rack 20, the facelate is provided with slots 29, through which the set-screws 28 pass.

The electrical connections are made in the usual way, in the present instance two of the wires or connections (not shown) being con nected with the adjusting-screws 17 18, and therefore to the electrical contacts 15 and 16, and the third wire or connection being connected with the base-plate 1, with which the circuit-closer or bar 10 is also in electrical contact through the metallic connections described.

The thermostat herein shown and described is com aratively simple in construction and reliable and efiicient in 0 eration. Moreover, the construction is such t at after the contacts are set or adjusted to the proper distance apart such distance may be maintained, although the contacts are shifted bodily to provide for an increased or decreased degree of temperature.

I claim- 1. The combination with a base-plate, 1, of a circuit-closer arranged therein and comrising a strip, 5, of expansible and contractile material and secured at its lower end to said base-plate, a supporting-lug, 7, secured to the base-plate and loosely engaging said stri a bell-crank-shaped lever pivoted to sai base-plate and having a long arm, 10,"

and a short arm, 13, a ca piece or ferrule, 8, engaging the upper end of ing an extension or arm, 9, engaging the short arm, 13, of the bell-crank, and electrical contacts, 15 and 16, between which said 1011 arm, 10, is adapted to operate; substantially as described. a

2. The combination with a base-plate, 1, of a circuit-closer arranged therein and comrising a strip, 5, of expansible and contractible material and secured at its lower end to said base-plate, a supporting-lug, 7, secured to the plate and loosely engaging said strip, a bell-crank-shaped lever pivoted to said baseplate and having a long depending arm, 10, and a short arm, 13, a cap-piece or ferrule, 8, engaging the upper end 0 said strip and having an extension or arm, 9, en aging the short arm, 13 of the bell-crank,anrf a coiled spring, 14, secured at one end to the stri the other end of which spring the long arm, 10, is adapted to contact; substantially as described.

3. A thermostat comprising a base-plate, a rod of expansible and contractible material, a block mounted on the base-plate and to which one end of said rod is secured, a lu supportin the other end of said rod and through w 'ch the same is adapted to slide, a bell-crank lever fulcrumed to the base in proximity to the movable end of said rod, a connection from said end to the short arm of the lever, two electrical contacts with which i the long arm of said lever is adapted alternatively to engage, a sliding dplate u on which said contacts are mounte said p ate being provided with rack-teeth on one edge, a shaft 0 asegment engaging said rackteeth, and a handle mounted on said shaft and adapted to move the same to move the plate and pointer.

4. A thermostat com rising a frame, two perforated lu mounted thereon, a thermostatic rod wit its two ends passing through said lugs, means for clamping one end of said rod to its associated lug, whereby the rod may be readily adjusted with relation to or removed from said lug, a bell-crank lever fulcrumed to the frame in proximity to the other lug, a connection between the free end of, the rod and the short arm of said lever, the lon arm of the lever extending parallel to said thermostatic rod, and an adjustable electrical contact with which the end of said long arm is adapted to engage.

5. A thermostat comprising a base-plate, a thermostatic rod having one end immovably and the other end slidably mounted on said base-plate, a contact-arm fulcrumed to the base-plate in proximity to the free end of said rod, a connection between said end and said contact-arm, contactpoints arranged in said strip and hav-' against proximity to the other end of said rod, and with which the free end of said arm is adapted to engage, a movable mounting for said contact-points, and a pointer operatively connected with said movable mounting and adapted to move therewith, said thermostatic rod, contact-arm and pointer being arranged parallel to each other and to the base, whereby a compact structure is obtained.

6. A thermostat comprising a base-plate and a faceplate, a thermostatic rod mounted on the base plate, a contact-arm mounted on the base-mate and arranged to be moved by the expansion or contraction of said thermostatic rod, two contact-screws with the points of which said contact-arm is adapted alternatively to engage, the heads of said screws projecting beyond the frame of said thermostat, and set-screws adapted to engage said contact-screws, the heads of said screws projecting through said face-plate into an accessible position, whereby the adjustment of the thermostat may be readily varied.

ARTHUR D. COLTON.

Witnesses:

' S. E. HIBBEN,

AMELIA WILLIAMS. 

